Optimization of Magnesium Solubility Factor in Production of Ductile Iron ‎using Gating System Addition Method

Running system design is one of the most important variables in the casting of ductile iron components by the In-mold process. In this research, a new gating system (based on the critical gate velocity) was used to cast the sample parts. The effect of three magnesium solubility factors (0.03 and 0.04 and 0.05) and three different reaction chamber heights and also the effect of chill on the microstructure and nodule counts in various position of the gate to the casting were investigated. Optical microscopy showed that the optimum nodule count and uniform distribution through the pieces achieved in the 0.03 solubility factor and 30 mm reaction chamber height. By increasing the reaction chamber height, the amount of spheroidization and the number of graphite in a square millimeter (nodule counts) decreased. Also, the higher cooling rate of the pieces results in higher nodule counts.